Phosphorus segregation index
The phosphorus segregation index measures the local phosphorus enrichment in cast or rolled products. It helps predict toughness losses, especially in core zones.
Physical-Chemical Mechanism of Action
The Phosphorus Segregation Index (PSI) is a metric that quantifies the local enrichment of phosphorus in metal products. It is calculated by measuring and comparing the phosphorus content at various points of a component.
Metallurgical Relevance & Risks in Welding
A high PSI can lead to a drop in toughness, especially in the core zones of cast products. This can cause cracks or weak points in the weld and impair the mechanical properties of the component.
Workshop Practice & Action Guidelines
To detect a high PSI, metal products should be carefully inspected after casting or rolling. If problems are found, the addition of alloying elements in the casting process can be adjusted to reduce the phosphorus content. Recommended PSI values are normally below 0.5. For values above 1, measures should be taken to reduce phosphorus.